Hi my name is Nate. I am a senior in high school aspiring to become a microbiologist. I heard about this podcast through a class I took on biotechnology and have been listening for about 2 months. I really enjoy it and the other two shows even if I don't quite understand everything you talk about, but I grasp most things. So a few weeks ago I attended a biotechnology summer academy for high school students where we study one certain topic for three weeks with a professor at the college it was at. My subject was about the microbes that make up the stromatolites in the Great Salt Lake and why it's important that we understand it. I learned that they are made of Cyanobacteria and certain types of archea. The Cyanobacteria don't really make sense because they don't have a very high salinity tolerance, especially as high as the GSL which is 33% at parts of the lake. But yet they are there. I also learned that the rock is formed by the waste of the microbes which is calcium carbonate. These rocks have the potential to help with global warming. I'm not saying that I agree with the idea of global warming or not, but it is happening a little bit. So that brings up the question, Can we harvest and "grow" these rocks in a lab until they are big enough to put into the wild to "catch" some of the carbon dioxide in the atmosphere? I would like to hear your input on this subject as I didn't have a lot of time at the academy to study it. Thanks
[I asked Hazel Barton, here is her reply]
Actually this is a pretty good question and a number of folks have thought
about microbial CO2 sequestration in just this way.
Many of the carbonate rock deposits (limestone) from about 360+ million
years ago were formed during high periods of CO2, and we believe the CO2
was sequestered as rock by microbial activity. It dropped the atmospheric
CO2 levels and preserved it in a form that is obviously stable over
geologic time scales.
The problem we have today is the ion. To precipitate CO2 as carbonate,
you need a divalent ion. In the ancient oceans, there was plenty of
calcium around, so it was deposited as calcium carbonate (limestone).
Unfortunately, that easy source of calcium has been exhausted, so the
problem comes in generating the ion for the carbonate to precipitate. It
takes quite a bit of energy to do synthetically, so there's no net loss of
greenhouse gases. If someone could come up with a handy ion, generated
from a more passive process (such as decomposition in garbage), then we
could certainly sequester CO2 this way.
A good PhD project!
The stromatolite question is quite a bit more complicated and has to do
with the saturation index of carbonates in seawater when the CO2 levels
drop (from photosynthesis) - I can elaborate on that more if you need, but
the ion is still problematic.
This Google Plus community knocks off socks when just skimming through the photos/captions! Don't want anyone to overlook it.
In TWIM #60 @1:06:23 Michael Schmidt suggests that glucose for fermentation from biomass is a necessary step in production of fuel ethanol. Fuel ethanol and other low molecular weight compounds can also be produced by autotrophic anaerobic fermentation of syngas. Syngas is a mixture of carbon monoxide, carbon dioxide, and hydrogen produced by pyroclastic treatment of a wide variety of organic material including ligno-cellulose, recycled tires, sewage sludge, and natural gas or methane. These reactions have been studied for many years and are being commercialized by Coskata. www.coskata.com.
Never underestimate the ability of microbes to scrounge a living from nearly any environment with water and energy available.
Hello TWiM team! Thank you for the hours of entertainment and education you provide. I have a somewhat morbid question for you that's fairly random--I forget what inspired it exactly--but it has been bugging me: normally when an animal dies, it decays, but what happens if that animal is totally free from all microbes? So, what happens if a germ-free mouse dies in a sterile environment and no one disposes of it for a while? Does it decay somehow, or just dry out maybe?
Thanks again for all you do,